Signs showing complications.

Demystifying Gastric Sleeve Complications

In Gastric Sleeve, Weight Loss Surgeries by OC Staff

Written by Dan Abeling, OC Staff

Gastric Sleeve surgery is a proven safe and effective procedure for weight loss. While gastric  sleeve surgery is the newest of the “approved” surgeries for weight loss, it has quickly gained favor from physicians and patients alike. The surgery may soon surpass Lap Band and gastric bypass in popularity.

Being overweight carries an increased risk of heart disease, an increased risk of developing diabetes, higher risk of complications from diabetes, increased risk of cancer, high blood pressure, higher levels of cholesterol, sleep apnea, and much more. The diseases caused or commonly associated with obesity and are referred to as co-morbidities.

Ultimately, weight loss surgery is a risk versus reward analysis. The risk is a complication, outlined below. The reward is a healthier, more energetic and often happier, you.


Before we discuss the complications associated with gastric sleeve surgery, it’s important to discuss the benefits.

  • It’s quicker and technically easier than gastric bypass surgery.
  • It results in an average of 60% excess weight loss.
  • More weight loss than Lap Band and slightly less than gastric bypass.
  • Reduces hunger.
  • Does not produce dumping syndrome like gastric bypass.
  • Does not require band adjustments like Lap Band surgery.
  • Weight loss is rapid. The majority of weight loss occurs in the first year after surgery.


A 2010 study at Stanford University shows an average mortality (death) rate of just .08%. That’s less than 1 person per 1000 procedures. Keep in mind, many of the patients in this study were severely obese and severly obese individuals have a higher mortality rate associated with any surgical procedure.

A study in 2011 by the Cleveland Clinic Florida revealed that gastric sleeve surgery had lower complication rates and reoperation rates compared to both Lap Band and gastric bypass. This study reviewed the outcomes of over 2,400 gastric sleeve patients.

Needless to say, gastric sleeve surgery is as safe if not safer than the other primary surgeries approved for morbid obesity.

Complications can happen at different points during and after your procedure. Some complications are very serious and life threatening, while others are minor. Knowing the difference is important.

As always, follow the advice of your surgeon. If you think you may have a complication, contact your surgeon immediately.

Common Complications During Your First 2 Weeks

Your first two weeks after surgery can be difficult. You are adjusting to your new diet. You are recovering from surgery. You are moody and in pain but you’re happy that you made it past surgery. The hard part is not over just yet. The most serious complications can occur during this time.

Graph showing rate of serious complication after sleeve gastrectomy.

Staple Line Leaks

During the first week after surgery the most feared and serious complication is a staple line leak. This is the why surgeons test, double check, and often oversew the staple line during a gastric sleeve procedure. They are trying to minimize the risk of the staple line leaking.

What to look for?

  • Fever
  • Increased heart rate
  • Difficulty or altered breathing.

When to call your doctor:

  • Always refer to your discharge instructions.
  • However, if you experience any of the symptoms above, it is recommended that you call your doctor.
  • If you are feeling light headed or have difficulty breathing, call 911.

How common are they?

According to this study, Sleeve gastrectomy and the risk of leak: a systematic analysis of 4,888 patients, the risk is about 2.4%.

How are they treated?

This typically depends on how far out you are from surgery.

  • 3 days and under
    • Exploratory laparoscopy (the surgeon goes back with a scope to see what is going on).
    • If he/she finds the leak, it is then surgically repaired.
    • A feeding tube is placed directly into the small intestines (jejunum).
  • 8 days or after
    • Because the inflammation process has started, surgery is typically not performed if the patient is stable.
    • With a stable patient, drainage, stents and establishing a feeding route is often the route of treatment.
    • If the patient is not stable, surgery is often performed to drain and wash out the area. The leak is repaired if possible or medically managed if not.

Thrombosis (blood clots)

Blood clots after any surgery can be life-threatening if not treated quickly. Hospitals and your Dialing 911 from your phone.physician are very aware of this risk and take measures to help prevent blood clots.

A thrombus is created when blood clots after injury (surgery) in an otherwise healthy blood vessel.

Clots are more likely to form when a blood flow is impaired due to a lack of mobility (common after surgery).

What to look for?

Typically these symptoms will appear in the arms or legs.

  • Redness
  • Swelling
  • Pain
  • Loss of sensation
  • Pale color in the extremity affected.
  • Paralysis

When to call your doctor:

  • Call your doctor immediately if you suspect you may have a blood clot.
  • Blood clots can lead to stroke, heart attack, and death.
  • Your doctor will recommend that you stay active shortly after surgery to reduce the risk of blood clots.
  • Smokers have an increased risk of blood clots.

How common are blood clots?

The risk of developing a deep vein thrombosis (blood clot) is very low (under 1%). However, if you develop a blood clot, the complications can be extremely serious.

How are they treated?

This depends on the size and location of the blood clot.

  • Surgery may be attempted to remove the clot.
  • Medication may be administered directly into the clot to dissolve it.


A stricture is when the opening to or from the stomach becomes inflamed and/or blocked preventing all or some of the food from properly entering the stomach or intestines.

Strictures can be either acute or chronic (very quick onset or an ongoing issue after surgery).

What to look for?

  • Nausea or vomiting.
  • Difficulty swallowing.
  • Food intolerance.

When to call your doctor?

  • As always call your doctor if you think something is wrong.
  • If nausea and vomitted is present every time you eat, or you are having difficulty swallowing, contact your doctor immediately.

How common is a stricture?

According to this study, strictures were present in about 3.5% of patients after surgery. However, while a stricture can be serious, often they are treated with a simple endoscopic dilation (inserting a camera down your throat under anesthesia to widen the stricture).

How are they treated?

  • If the stricture is diagnosed shortly after surgery, it can usually be treated with rest, nothing by mouth, and intravenous fluids.
  • If the stricture is diagnosed a few weeks or more after surgery then the treatment will depend on the length of the stricture.
    • For short stenosis (narrowing of the stomach) the physician will typically perform an endoscopic dilatation.
      • Multiple treatments every 4 to 6 weeks will typically clear the stricture.
    • For longer stenosis, the phsyician may have to intervene surgically and convert the patient to gastric bypass.

Wound Site Infection

A wound site infection is an infection at or under the area where the surgeon made the small incisions for their instruments.

Wound site infections can happen after any surgery. Obesity carries a higher risk of surgical site infections post surgery. If infections are not treated promptly with antibiotics, tissue death, widespread infection, and death may occur.

What to look for?

  • Fever.
  • Redness at incision site.
  • Increased heart rate.
  • Dizziness/lightheadedness.
  • Heat at the incision site.

When to call your doctor:

Always follow your doctor’s post-operative guidelines for proper care of your wounds after surgery.

  • It is recommended to call your doctor immediately if you suspect you may have a wound site infection.

How common are wound site infections?

They are pretty common. This study shows a range of 10% to 15% for post-operative wound site infections.

How are they treated?

Infections are usually treated with antibiotics, removing sutures, washing out of the wound site, and often antimicrobials.

The length of treatment and seriousness of the infection varies based on the type of bacteria related to the infection. MRSA, Staph and other infections can require intense treatment to prevent their spread.

Common Long-term Complications

These are complications that occur anytime after your surgery. They are typically not life-threatening. Nonetheless, they are not pleasant.

Graph showing long-term sleeve complication rates.

Nutritional Deficiencies

While nutritional deficiencies are less common compared to gastric bypass or duodenal switch surgery, there is a risk.

In fact, about 12% of patients experience nutritional deficiencies after sleeve gastrectomy.

What to look for?

  • Abnormally pale skin.
  • Fatigue.
  • Hair loss.
  • Lightheadedness.
  • Constipation.Vitamins and supplements after surgery.
  • Menstural issues.
  • Inability to concentrate.

When to call your doctor:

Unless your symptoms are severe and you’re unable to take your recommended supplements this is something to bring up with your doctor at your next appointment.

How common is it?

Studies show about 12% of patients can experience nutrient deficiencies.

How is it treated?

  • Supplements.
  • Diet.
  • Regular blood work. (i.e. every 3 months)


Gallstones are very common after gastric sleeve surgery. This study shows gallbladder disease in as many as 23% of sleeve patients (within two years after surgery).

What to look for?

  • Pain in the upper abdomen and upper back. Sometimes lasting a few hours.
  • Nausea
  • Vomiting
  • Bloating, indigestion, heartburn and gas.

When to call your doctor:

Go to the Emergency Room if you are experiencing intense pain. Let you doctor know if you are experiencing bloating, gas and heartburn.

How is it treated?

  • Surgery is indicated to prevent continued worsening of gallbladder disease.
  • Surgery is simple and generally straightforward.

GERD (Heartburn)

GastroEsophageal Reflux Disease (heartburn) is common after weight loss surgery. There is varying evidence whether or not it is increased or decreased after gastric sleeve surgery. However, some studies report up to 47% of patients will experience GERD after surgery.

How is it treated?

  • Medication – Proton Pump Inhibitors are the common treatment.
  • If GERD remains persistent after medication, surgery can be performed.

Complications During Surgery

There are a number of potential complications that can happen during gastric sleeve surgery. We’ve included them at the end of this post because most of them are easily managed during surgery. And if they are overlooked or not managed correctly then they show up in the first two weeks after surgery.

Intraoperative complication rates are low but can happen. The following complications can occur during your surgery.

Gastric leak (stomach leak typically at staple line)

  • Your new stomach (about 15% the size of your old stomach) is usually tested using an air or dye test before finishing the procedure. This limits the risk of an unnoticed leak. However, if not tested properly a leak could lead to infection and death.
  • Some surgeons will also test using an EGD (Esophagogastroduodenoscopy) to better visualize the staple line from the inside.
  • Staple lines can be secure during a procedure but due to different healing factors can subsequently leak in the weeks after surgery.
  • A gastric leak is the biggest single risk after surgery.

Unnoticed gastric laceration.

  • The surgeon can accidentally lacerate (cut) the stomach without noticing or properly fixing it prior to closing.

Other Complications During Surgery

  • Enlarged liver obstructing visibility
    • An enlarged liver is common with bariatric patients. All bariatric surgeons will put you on a pre-operative diet. This usually starts 2 weeks prior to surgery.
    • It is very restricted in calories, carbohydrates and fats.
    • This reduces the size of your liver prior to surgery which makes surgery easier.
    • If you do not follow the pre-op diet and your liver is too large the surgeon may end up cancelling your surgery due to the increased risk of liver trauma or trauma to the surrounding tissues due to poor visibility.
    • You can read more about fatty liver disease here.
  • Adhesions
    • Adhesions are typically caused by prior abdominal surgery or illness(i.e. severe endometriosis).
    • Your internal tissues stick together when recovering from prior surgery or illness.
    • This causes the surgeon to remove the adhesions to visualize and/or free up the area that he needs to work on (your stomach).
    • This can occasionally lead to an open procedure if the surgeon cannot safely take down the adhesions via a laparoscopic approach.
  • Controlled bleeding
    • While it’s possible to lose blood during surgery, if it’s controlled quickly it’s not an issue.
  • Spleen injury.
    • These are rare but can happen particularly if the patient didn’t follow their pre-op diet and the surgeon struggles to visualize properly.
  • Liver Injury
    • While typically not serious, undiagnosed liver trauma can lead to significant blood loss, infection and even death.
  • Uncontrollable bleeding.
  • Cardiovascular problems (undiagnosed heart disease), stroke.
  • Anaphylaxis (severe allergic reaction) due to anesthesia.

Other References

5 Year Results in A Military Institution

Dr. Gordon Wisbach; David M. Lim, DO; William Bertucci, MD; Janos Taller, MD; Robert H. Riffenburgh, PhD, MD; Jack O’Leary, RN

*PL-104: National Comparisons of Bariatric Surgery Safety And Efficacy: Findings from the BOLD Database 2007-2010

Dr. John Morton; Bintu Sherif, Deborah Winegar, PhD; Ninh Nguyen MD, FASMBS; Jaime Ponce, MD, FASMBS; Robin Blackstone, MD, FASMBS

*PL-133: Procedure Related Morbidity Comparing Roux-en-Y Gastric Bypass, Sleeve Gastrectomy And Laparoscopic Adjustable Gastric Band: A Retrospective Long Term Follow Up

Dr. Raul J. Rosenthal; Abraham Fridman, DO; Karan Bath, MD; Andre Teixeira, MD; Samuel Szomstein, MD, FASMBS


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